Move NIF record index back to a separate user object

This makes sure it's never erroneously optimized out. NodeIndexHolders don't need to be cloned as their record index is never supposed to be changed.

components/nifosg/matrixtransform.cpp

@@ -7,9 +7,8 @@ namespace NifOsg
     {
     }
 
-    MatrixTransform::MatrixTransform(int recordIndex, const Nif::Transformation &trafo)
+    MatrixTransform::MatrixTransform(const Nif::Transformation &trafo)
         : osg::MatrixTransform(trafo.toMatrix())
-        , mIndex(recordIndex)
         , mScale(trafo.scale)
         , mRotationScale(trafo.rotation)
     {
@@ -17,7 +16,6 @@ namespace NifOsg
 
     MatrixTransform::MatrixTransform(const MatrixTransform &copy, const osg::CopyOp &copyop)
         : osg::MatrixTransform(copy, copyop)
-        , mIndex(copy.mIndex)
         , mScale(copy.mScale)
         , mRotationScale(copy.mRotationScale)
     {

components/nifosg/matrixtransform.hpp

@@ -12,7 +12,7 @@ namespace NifOsg
     {
     public:
         MatrixTransform();
-        MatrixTransform(int recordIndex, const Nif::Transformation &trafo);
+        MatrixTransform(const Nif::Transformation &trafo);
         MatrixTransform(const MatrixTransform &copy, const osg::CopyOp &copyop);
 
         META_Node(NifOsg, MatrixTransform)
@@ -29,9 +29,6 @@ namespace NifOsg
         // Apply the given translation to OSG matrix.
         void setTranslation(const osg::Vec3f& translation);
 
-        // NIF record index
-        int mIndex{0};
-
     private:
         // Hack: account for Transform differences between OSG and NIFs.
         // OSG uses a 4x4 matrix, NIF's use a 3x3 rotationScale, float scale, and vec3 position.

components/nifosg/nifloader.cpp

@@ -43,6 +43,7 @@
 #include <components/sceneutil/morphgeometry.hpp>
 
 #include "matrixtransform.hpp"
+#include "nodeindexholder.hpp"
 #include "particle.hpp"
 
 namespace
@@ -487,7 +488,7 @@ namespace NifOsg
                 break;
             }
             if (!node)
-                node = new NifOsg::MatrixTransform(nifNode->recIndex, nifNode->trafo);
+                node = new NifOsg::MatrixTransform(nifNode->trafo);
 
             if (nifNode->recType == Nif::RC_NiCollisionSwitch && !(nifNode->flags & Nif::NiNode::Flag_ActiveCollision))
             {
@@ -522,6 +523,12 @@ namespace NifOsg
             if (!rootNode)
                 rootNode = node;
 
+            // The original NIF record index is used for a variety of features:
+            // - finding the correct emitter node for a particle system
+            // - establishing connections to the animated collision shapes, which are handled in a separate loader
+            // - finding a random child NiNode in NiBspArrayController
+            node->getOrCreateUserDataContainer()->addUserObject(new NodeIndexHolder(nifNode->recIndex));
+
             for (Nif::ExtraPtr e = nifNode->extra; !e.empty(); e = e->next)
             {
                 if(e->recType == Nif::RC_NiTextKeyExtraData && textKeys)

components/nifosg/nodeindexholder.hpp

@@ -0,0 +1,35 @@
+#ifndef OPENMW_COMPONENTS_NIFOSG_NODEINDEXHOLDER_H
+#define OPENMW_COMPONENTS_NIFOSG_NODEINDEXHOLDER_H
+
+#include <osg/Object>
+
+namespace NifOsg
+{
+
+    class NodeIndexHolder : public osg::Object
+    {
+    public:
+        NodeIndexHolder() = default;
+        NodeIndexHolder(int index)
+            : mIndex(index)
+        {
+        }
+        NodeIndexHolder(const NodeIndexHolder& copy, const osg::CopyOp& copyop)
+            : Object(copy, copyop)
+            , mIndex(copy.mIndex)
+        {
+        }
+
+        META_Object(NifOsg, NodeIndexHolder)
+
+        int getIndex() const { return mIndex; }
+
+    private:
+
+        // NIF record index
+        int mIndex{0};
+    };
+
+}
+
+#endif

components/nifosg/particle.cpp

@@ -11,7 +11,7 @@
 #include <components/nif/controlled.hpp>
 #include <components/nif/data.hpp>
 
-#include "matrixtransform.hpp"
+#include "nodeindexholder.hpp"
 
 namespace NifOsg
 {
@@ -381,11 +381,16 @@ void FindGroupByRecIndex::apply(osg::Geometry &node)
 
 void FindGroupByRecIndex::applyNode(osg::Node &searchNode)
 {
-    if (NifOsg::MatrixTransform* trans = dynamic_cast<NifOsg::MatrixTransform*>(&searchNode))
+    if (searchNode.getUserDataContainer() && searchNode.getUserDataContainer()->getNumUserObjects())
     {
-        if (trans->mIndex == mRecIndex)
+        NodeIndexHolder* holder = dynamic_cast<NodeIndexHolder*>(searchNode.getUserDataContainer()->getUserObject(0));
+        if (holder && holder->getIndex() == mRecIndex)
         {
-            mFound = trans;
+            osg::Group* group = searchNode.asGroup();
+            if (!group)
+                group = searchNode.getParent(0);
+
+            mFound = group;
             mFoundPath = getNodePath();
             return;
         }

components/sceneutil/serialize.cpp

@@ -143,6 +143,7 @@ void registerSerializers()
             "NifOsg::GeomMorpherController",
             "NifOsg::UpdateMorphGeometry",
             "NifOsg::UVController",
+            "NifOsg::NodeIndexHolder",
             "osgMyGUI::Drawable",
             "osg::DrawCallback",
             "osgOQ::ClearQueriesCallback",